High speed baking in novel toasting apparatus

ABSTRACT

An electric baking oven includes an open mesh vertically oriented baking basket to hold food while the food is baked in air by a programmed combination of radiant and convective and conductive energy transfer. An electrical programming control controls the energy from vertically oriented toaster heating elements located juxtaposed to the large vertical faces of the basket and from at least one elongated heating member located below the vertical baking basket with the axis of the elongated heating member oriented nominally horizontal and parallel to the longer horizontal axis of the vertically oriented baking basket.

CROSS REFERENCE TO RELATED APPLICATION

This application is a division of application Ser. No. 10/428,143, filedApr. 30, 2003, now U.S. Pat. No. 7,036,424, which is a division ofapplication Ser. No. 09/917,996, filed Jul. 30, 2001, now U.S. Pat. No.6,584,889, which is a continuation in part of application Ser. No.09/569,841, filed May 12, 2000, now U.S. Pat. No. 6,267,044, which isbased on provisional application Ser. No. 60/133,914, filed May 13,1999.

BACKGROUND OF INVENTION

Parent U.S. Pat. No. 6,267,044 describes a toaster which containsheating elements optimally designed and positioned for toasting andprovides the means to preheat the toasting elements to optimal thermalconditions for toasting before introducing the bread or other materialto be toasted into the toasting environment. The novel toaster designdisclosed in that patent includes also added means to create the optimalconditions for baking, warming, defrosting or a combination thereof. Thedesign geometry, size and thermal environment of the relativelyubiquitous conventional toasters have not proven satisfactory forquality baking, defrosting or warming. By contrast this toaster willperform these functions faster and better than conventional baking ovenscommon to virtually all kitchens.

Conventional baking ovens that have been used for centuries are designedwith horizontal shelves to cook food in horizontal containers that areslowly raised to elevated temperatures by heated air. Food in thosecontainers is heated primarily by contact with the hot horizontalcontainer or by contact with adjacent food in turn heated by contactwith the container.

In more recent times motor driven fans have been introduced in ovens tocirculate the air around the containers and over the top of foods inhorizontal containers or horizontal shelves. Large electrical heatershave been added on the ceiling, floors and side walls of ovens to heatthe air more rapidly. Horizontal shelves are provided universally as themeans to hold food containers and in some cases to position bread orother foods horizontally in close proximity to a horizontal mountedheater that will toast or broil one side at a time. The efficiency ofthe toasting operations is very poor taking many minutes totoast—leaving a dry relatively unappetizing product. Large ovens of thatsort take 10 or more minutes just to reach baking temperatures andsubstantial time to complete the baking because of inefficient heattransfer to the food. No provision is made in such ovens to insureintimate and direct contact with all surfaces of the food when that foodis particulate or simultaneously with both sides of the food if the foodis planer such as steaks, patties, and waffles. An exception to that isthe rotisserie that secures larger foods on skewers and rotates thembefore the heated air, flames, or heated elements.

SUMMARY OF INVENTION

The present invention is directed to techniques for optimal bakingcycles in the unique toaster of parent U.S. Pat. No. 6,267,044.

This invention describes the means and mechanism to hold particulatefood within a toaster so that there is direct and intimate contactbetween heated air and virtually all the foods surface area to insurerapid and uniform heating of the food by naturally convective transferfrom hot air at baking temperatures in combination with programmedtemperature radiant energy from toasting elements and at least oneauxiliary heater operating at optimum temperatures which are differentfrom those that must be employed in an optimal toasting cycle. Thisprogrammed combination of heating by the hot air and radiation providesoptimum baking rates without overheating the exposed surfaces of thefood in such a manner as to create excessive or burning of the foodsurface. By this new methodology and by the close proximity of theheating system and the toasting elements it is possible to optimize thebaking conditions for the effective baking of hundreds of uncooked or“precooked but not browned” foods available for quick bake-and-servedishes. Unlike conventional ovens and toasters which cook slowly andunevenly, the means disclosed here bakes rapidly and uniformlysimultaneously on virtually all surfaces of particulate foods creatingtasty uniform temperature foods as a result.

Many ovens and so called toaster-ovens can be used for toasting but thetoasted food lies flat and must be turned over to complete the toastingor to achieve relatively uniform toasting on each side. Those heaterelements are not optimized for toasting. In the baking mode inconventional ovens there is little motion of the air over or through thefood, rather the air is relatively quiescent. Convection ovens with fansgenerate a general air flow within the oven but these are not designedto circulate air through a bed of particulate food—such as frozen frenchfries. Conventional toasters are used today in an attempt to “cook” manyof the frozen “precooked but not browned” foods by simply repeating thetoasting cycle several times. The results are very disappointingcreating overcooked and undercooked areas—sometimes burnt before gettingsufficiently warm on the interior. Good baking requires less intenseheat in order that the interior can be warmed sufficiently before thesurface is overheated or burnt.

No provision is made in such ovens for vertical open baskets to hold thefood and to allow air to pass through a bed of particulate food—such asfrozen french fries.

There have been attempts to offer toasters that combine the toasting andbaking functions such as U.S. Pat. No. 2,862,441 by W. A. Schmall (Dec.2, 1958) assigned to General Electric. This describes a combination unitwhich uses movable mirrors to redirect radiant energy upward fortoasting or downward to a separate baking compartment. That bakingfunction can not be particularly effective since the heat was appliedonly by the mirrors to one side of the food.

In contrast to prior art the subject baking appliance is designed firstas an optimal toaster. Baking is accomplished in the same space with theuse of an auxiliary air heater mounted below the baking space and withthe use of sophisticated electrical and electronic control of thetoasting elements to equalize air temperatures and to generate naturalconvection currents of the heated air through and around verticallyconfigured open mesh basket that contains the particulate food. Therelative amounts of heat provided by the toasting elements and by theauxiliary air heater are electronically controlled to optimize thebaking rate while avoiding excessively localized heating of the foodsurface by either the localized air temperature or the radiation fromtoasting elements. The toasting elements are segmented so that they canbe heated individually or together and thus temperature is controlled soas to optimize the air temperature along the vertical face of thevertical open mesh basket which holds the food to be baked.

U.S. Pat. No. 6,267,044, the details of which are incorporated herein byreference thereto, describes many of the novel aspects of this new batchtoaster in particular means for retaining the food to be toasted remotefrom the toasting zone until the thermal conditions in the toasting zoneare optimal for toasting. By that means the bread or other food to betoasted is when entered into the toasting zone, toasted rapidly avoidingunnecessary drying of the food that would otherwise take place beforethe ambient thermal conditions are optimal for toasting of the foodsurface. Consequently the toasted food loses less internal water and canbe crisp on its exterior surface while retaining more of its internalmoisture. The food to be toasted is placed on a carrier of some sort andtransported either manually or automatically into the toasting zone whenthat zone is thermally optimal for toasting.

For toasting to occur rapidly, and thus reduce the loss of moisture fromthe food, it is best that heat transfer be largely by radiation and lessby a combination of hot air conduction and convection where heattransfer is inherently slower limited by the thin layer of air in theboundary layer adjacent the food surface. Heat transfer through suchboundary layers is inherently slower while radiation can pass literallyat the speed of light uninhibited from the radiant source onto the foodsurface. When toasting this speed is advantageous. When baking one hasto monitor and control carefully the amount of radiant energy so as toavoid burning the surface of the food before the interior is adequatelybaked. For the interior of the food to be baked sufficiently, heat mustbe first transferred to the surface of the food, whence heat must travelby conduction to the middle of the food thickness. The latter takes timebecause the thermal conductivity of food is poor and the amount of heattransferred is driven only by the elevated surface temperature of thefood. The higher the surface temperature the better up to the pointwhere the surface is overheated and begins to burn or overcook.Consequently the surface temperature must be carefully controlled andlimited to avoid burning but it must be hot enough to drive effectivelythe heat below the food surface where it is needed to evaporate excesswater and to dehydrate and crosslink the food proteins or break chemicalbonds.

Toasting, a surface phenomenon, can be forced to occur rapidly. Bycontrast baking rates are limited by the slow transfer of heat throughthe full thickness of foods. Baking cannot be rushed without danger ofburning the surface. This is why toasters are notoriously poor forbaking. The intensity of toasting elements must be moderated if they areused during extended baking to assist in heating the surface of foods.Radiation from toasting elements will not shine onto all food surfaceswithin a bed of particulate food. Shadowing effects limit theeffectiveness of direct radiation. Heat for the surface of interiorparticulate surfaces can be well provided by convective and conductivetransfer from hot air circulating around and between the particulatefood.

From the above it is clear that a thermal environment ideal for toastingis not suitable for quality baking. Similarly the environment optimalfor baking is totally unsatisfactory for toasting. What this inventorhas discovered is that it is possible to bake efficiently and rapidly inthe toasting space by using segmented electrical toasting elementsoperating at reduced temperature as auxiliary heaters to supplement aremote efficient heating means to elevate the air temperature within theenclosure and to generate natural convection current around and througha bed of particulate food adjacent to the toasting elements. The bakingprocess can be optimized by programming independently the temperature ofthe segmented toasting elements and the remote heating means throughoutthe baking cycle. In the relatively short initial heat-up phase of thebaking cycle (approximately 1 ½ minutes) both the upper and lowertoasting segments are powered to an elevated temperature equal to orslightly lower than their temperature when toasting. This provides aninitial burst of radiant and convective heat transfer that elevates thetemperature of the food surface and hastens the overall temperature riseof the enclosed air, the oven walls and the baking basket. In theinitial phase the remote heater also operates at or close to full powerto hasten the heat-up process. Temperature within the baking space ismonitored to determine when it has reached the desired bakingtemperature. After that time usually less than 2 minutes, the toasterelements are operated at reduced temperature and the power applied tothe remote heater and to the toaster element is controlled to maintainthe oven temperature at the desired temperature.

Any of a variety of electrical control means can be used to programduring each portion of the baking cycle the appropriate amount of powerto the toasting elements and to the remote heating means. A solid staterelay controlled by an oven temperature sensing means provedparticularly effective for controlling power to the various heatingelements.

This inventor has found that the uniformity and speed of baking ofparticulate foods is enhanced significantly if the food is held in anelongated vertically oriented mesh basket of cross section sufficientlysmall that heated air can readily pass by naturally convective meansthrough the basket thus contacting efficiently the surfaces of theparticulate food held therein. Using a specific arrangement of heatingelements and by employing a vertical basket of approximately 1 ¾ to 3inch thickness (between the large vertical mesh faces) naturalconvection of the heated air passes rapidly through such a basketinsuring that the particulate food is uniformly heated and bakedthroughout the basket.

A vertical configuration of the baking basket is optimal and it isconsistent with the toasting geometry optimal for toasting as describedherein and in parent U.S. Pat. No. 6,267,044. The elongated verticalorientation of the baking basket allows toasting heating elements ofsimilar orientation to be used effectively to aid in the heating processand to apply heat uniformly to the face of the elongated vertical bakingbasket.

By using an elongated relatively high power heater (approximately600-1000 watts) under the basket, air heated by this means risesnaturally by virtue of its reduced density along the vertical faces ofthe mesh basket. By physically offsetting the heater slightly, on theorder of a quarter inch or so from the long center line of the bakingbasket it was found that there is greater air flow up one side of thebasket creating enough pressure difference between the faces of thebasket to force a significant fraction of the hot air through thethickness of the mesh and across the surfaces of the cooler particulatefood. It was found convenient to use a high temperature elongated sourcesuch as a cal-rod or a quartz-enclosed conventional hot wire heater.Because of the high temperature required for efficient heat transfer toair by such a source it may be hot enough to radiate significant energy.In that event the bottom of the mesh basket is best shielded from thedirect radiation emitted by the heating source. One way to prevent thedirect radiation from shining on the food basket is to locate thatsource in a relatively open but roofed compartment below the foodbasket. The mesh baking basket can be supported by, but spaced above anintegral solid metal base. The bottom of the open mesh basket shouldoptimally be positioned at least ⅜″ above any such base. By these meanshot air can ascend up through the mesh bottom of the basket. Either themetal base or the roof of the heater compartment will shield the foodfrom direct radiation from the lower heater.

More than one air heater can be used below the baking basket and theirpositioning can be arranged to provide greater air flow up one face ofthe basket and then pass the other to create a pressure differenceacross the faces of the basket and flow through the basket.

The elongated vertical configuration for the baking basket has provenideal because it conforms directly with the planar geometry of thetoasting heater boxes and it allows air heated from below to passuniformly upward along and across the entire large faces of the bakingbasket and through the particulate food. The advantages of thisarrangement can be readily visualized in comparison to the use ofconventional horizontal pans, horizontal trays or open mesh shelving.None of these conventional baking configurations offer the possibilitysimultaneously for the symmetry and proximity of auxiliary planarheaters such as the toaster elements adjacent both major faces of thebasket as described here nor do they offer opportunity forsimultaneously creating uniform naturally convective air currents alongboth sides of the food basket and through its food bed.

The effectiveness of the natural convective hot air currents through thecool food was demonstrated by detailed temperature measurements of thefood temperature and the air temperature adjacent to the baking basket.It was observed when the long axis of the lower heater was offset ¼ inchor so from the lower center line of the basket, convective air currentsthrough the food increased sufficiently to equalize the air temperatureadjacent to the food to that of the rising main air stream. When thelower heater was centered the air temperature adjacent the cool fooddropped below the temperature of the air above and below the food levelreflecting much less convective circulation through the food. When theheater was set off center the food cooked (reached ultimate temperaturefaster) and it was cooked more uniformly throughout the food bed.

This unique toaster and baker is designed to optimize separately itsperformance for each of these two functions. None of the known batchtoasters preheat the toasting element and toasting environments beforetoasting to create the crispy yet moist texture. None of the known batchtoasters are effective for baking. Toaster ovens are available thatoffer the ability to either toast or bake. They do not offer means tooptimize the toasting environment before introducing the bread. Neitherdo they offer optimal means to bake in a vertical basket by combiningthe heating advantages offered by precise and programmed control ofadjacent planer toasting elements and a remote heater to generateefficient heated air convection currents past and through a bed ofparticulate food.

THE DRAWINGS

FIG. 1 is a perspective view of a baking oven in accordance with thisinvention;

FIGS. 2-3 are cross-sectional views in elevation showing the bakingelement of FIG. 1 in different phases of operation;

FIG. 4 is an enlarged elevational view showing the toasting basket ofFIGS. 1-3;

FIGS. 5-6 are perspective views showing the toasting basket of FIG. 4 inits opened and closed positions, respectively;

FIG. 7 is a longitudinal cross-sectional view showing the toastingbasket of FIGS. 1-6 lowered into the toasting zone;

FIG. 8 is a view similar to FIG. 7 showing the toasting basket in itsopened condition;

FIG. 8A is a cross-sectional view taken through FIG. 8 along the line8A-8A;

FIGS. 9-10 are views similar to FIG. 2-3 showing the oven used forbaking in accordance with this invention;

FIGS. 11-12 are perspective views of a baking basket in its closed andopened conditions, respectively; and

FIG. 13 is an enlarged cross-sectional view in elevation of a drivemechanism which may be used for the oven in accordance with thisinvention.

DETAILED DESCRIPTION

The unique design of this toaster and baker is based upon that describedin parent U.S. Pat. No. 6,267,044, the details of which are incorporatedherein by reference thereto. The baking basket and the baking functionare described in the following

FIG. 1 is an overall view of this new toaster/baker 10. An electroniccontrol pad 2 is provided so that the user can select either toast orbake. If toasting there is a choice of the toasting cycle either; (a) topreheat the toasting chamber before toasting or; (b) to introduce thebread or other food before heat-up. The first sequence creates a toastwith crisp exterior and a moist interior, the second creates a driertoast crunchier throughout its thickness. There are controls on panel 2also for selection of the baking temperature and time of bake.

The toaster/baker 10 outer shell 12, FIG. 2 is generally made of plasticspaced an appropriate distance outside an inner metal shell 12A thatencloses the heated oven. Air intake openings 4 along the bottom of thetoaster/baker 10 allow cool room air to enter and rise in the space 5,between the inner shell 12A and the outer shell 12, as shown in FIG. 2.The air removes heat from that space 5, rises as it is heated by the hotinner shell 12A and exits vents 3 located at the top of the toaster. Thevents 3 can be located either as shown in FIG. 1 or on the exterior sideof the opening 16 in top wall 14.

The same appliance may be converted to and from a toaster and a bakingoven in accordance with the electrical controls selected and with thetype of basket used for the food. Food to be toasted is inserted in atoasting basket 18 shown in FIGS. 2-6. Food items to be baked areinserted in baking basket 7, FIGS. 9-12.

For toasting, the toasting basket 18, FIGS. 5 and 6, is inserted intothe large toaster opening 16, FIG. 3 in an unheated waiting zone abovetoasting zone 26. The bread 25 or other food to be toasted is readilyinserted in the basket 18 on tray 20, FIG. 5. The hinged rails 22 and 24which are pivoted at their lower ends to mounting structure 28, arenormally held in the open position by springs 30 that pull these railsoutward as shown in FIGS. 4 and 5. When the toasting basket is loweredinto the toasting zone 26 the rails are in the open position. When thetoasting basket is lowered the toasting cages 38, FIGS. 2 and 3, locatedinside the toasting zone 26 advance toward the bread or other food inthe toasting basket, the toasting cage engages the hinged rails and bymeans of spring rod 35 presses them lightly against the food to move thefood to the center line of the basket and to hold it upright during thetoasting cycle. As shown in FIGS. 4-6 stop member 29 limits the outwardmovement of the basket rails.

In the toasting mode food is placed in the toasting basket 18 where inone option it is held in the waiting zone until the temperature in thetoasting zone 26 is optimal. The basket is then lowered by means ofmotor 48 of FIG. 7 into the toasting zone. As the basket is lowered thecontact arms 32, FIGS. 2 and 3, attached to the toasting basket contactsthe actuating arm 34 which is rigidly fastened to spring rod 35. Springrod 35 then moves the toasting heater cages 38, FIGS. 2, 3 and 7 awayfrom its location near wall 12A and into contact with the hinged rails22 and 24 of the toasting basket pressing the rails into contact withthe bread or other food to be toasted. Retraction springs 42 attached tothe cages 38 serve to pull the toasting heater cages back and away fromthe toasting basket when the toasting cycle is completed. Cages 38 maymove back and forth between the positions shown in FIGS. 2 and 3 in anysuitable manner such as by the provision of pins 37 mounted to the lowerend of each support arm 36,36 and mounted to partitions 59,59 as shownin FIGS. 8 and 8A. Parallel support arms 36, FIGS. 2 and 3, serve tokeep the toaster heater cages 38 nominally vertical and parallel to thetoasting basket as the cages are moved forward or retracted. It isdesirable during toasting that the hot wire elements 40A and 40B in thetoaster heater cage be operated at a high luminous temperature—about1600° F. to toast as rapidly as possible, without burning, in order totoast with minimal loss of water from the bread or other food. By thismeans the toasting cycle can be completed in about 45 seconds to 1minute. The other heating element 44 is an elongated heating memberlocated below the toasting basket that is not used during the toastingcycle. As the toasting basket returns the toasted food to the top of thetoaster, the bottom of the toasting basket seals off the toastingchamber so that on the next cycle the toasting zone can be reheatedwithout heating significantly the bread or other food held in thetoasting basket while the toasting zone is being reheated.

Either the toasting basket 18 or the baking basket 7 can be mounted onthe carriage support arm 21, FIGS. 2, 3 and 7 which is raised andlowered by the motor 48. The upper surface of the carriage support arm21 is U shaped to hold securely either of the baskets 18 or 7. Thesupport arm is cantilevered off of support bracket 56, FIG. 7 which inturn is supported on the carriage support rod 60. Two roller bearings 58attached to the bracket 56 support the weight of the carriage supportarm and either food basket with its load of food. The far end ofcarriage support arm 21 rides in an enclosed guide, such as slot 63, atthe end of the toasting compartment to maintain horizontal alignment ofthe carriage support arm. The enclosed slot 63 prevents loss of heatfrom the oven environment. The carriage support 21 is raised or loweredby the attached threaded nut 54 that is driven up or down the threadeddrive screw 52, (supported by end bearing 61) by the gear train 50driven by the motor 48. See FIGS. 7, 8 and 13. Partition 59 isolates themotor drive section thermally, from the heated toaster/bakingenvironment. As needed, thermal insulation can be added to the partitionwall to further reduce heating of the motor and drive elements. Thecarriage support arm extends from the motor compartment through a narrowelongated slot in the partition wall 59. Heat transfer through that slotcan be minimized during the heating cycle (when the baskets are lowered)by incorporating solid wall end plates 64 as shown on the end of thebaking basket, FIGS. 11 and 12.

The baking basket assembly 7 is detailed in FIGS. 11 and 12. Assembly 7is shown partially lowered into the baking zone, FIG. 10, and fullyinserted in FIG. 9. This assembly has an attached solid bottom tray 8that serves to catch and contain any grease or crumbs that will fallfrom particulate or other food placed in the mesh basket 6. This baskethas two vertical mesh side panels 6A that are hinged 9 so that they canlie flat, FIG. 12, when removed from the toaster to assist easy removalof food after cooking. The basket has a mesh bottom 6B spaced ½ inch orso above the bottom tray 8. This spacing is critical to allow naturalconvection of the heated air rising from the lower chamber to circulateup through the mesh bottom and through the food in that area. The meshconstruction of the large vertical faces 6A allows very free convectivehot air circulation through those faces and the food. It is important ofcourse that the width of the basket, that is the distance between thelarge vertical faces, does not become excessive and as a consequencerestrict the convective flow rate across the food bed. The length of thebasket is not critical other than it must correspond roughly to thelength of the toasting elements in order that they can be effective intransferring heat along the entire length of the basket. The height ofthe basket likewise should not extend significantly higher than thetoasting heater cage for most effective heating by the toasting heaterelements. The practical thickness of the mesh basket for foods such asfrench fries is less than 3 inches. For looser packed foods such asonion rings a thicker basket could be used.

As stated earlier the vertical configuration of the basket is criticalin order to make effective use of the vertical planer configuration ofthe toasting heaters and to make effective use of an auxiliary heater toinduce significant natural convection currents through the food bed.This is an optimal combination which avoids the necessity to add acirculating fan to force greater airflow in order to bake uniformly.

The baking basket assembly shown in FIGS. 11 and 12 has closed end walls64 each terminated at the top with plastic handles 66 that remainoutside the baking zone and hence remain sufficiently cool to allow thebasket assembly to be readily removed from the toaster.

The vertical mesh sides of the basket when raised to the verticalposition are held in place by retaining clips 11 attached to end walls64. Along the top of the basket, FIG. 11, are two hinged planar coverlids 65 which are automatically closed as the basket assembly descendsinto the toaster. Their closure is effected by the shape of the twoclosure latches 62 attached to the lid 65 as they pass shoulder 14 wherethe outer toaster cover 12 meets the vertical face 15 (FIG. 1) definingthe top opening slot of the toaster. The two planar cover lids 65 do notcompletely close off the top of the basket as they drop, rather theyleave an air gap slot about ¼ inch wide. This air gap allows some hotair to escape out the top of the baking zone when baking. The width andshape of that slot is optimized to insure more uniform temperaturethroughout the baking basket, to assist the upward flow of hot airaround and through the food and to avoid creating an excessively hotlayer of air just under the lids. A delicate balance of the power to theheating elements and the amount of air flow up and out of the toasterwhen baking is important to the quality and uniformity of the baking.

As shown in FIG. 12 the tray 8 extends substantially the entire lengthof the bottom wall of the mesh basket 6. As shown in FIGS. 11-12 each ofthe cover lids 65 extends substantially the entire length of its sidewall 6A.

Small flanges 67 extending at an angle from the hinged baking basketlids 65 serve to minimize leakage of hot air from the baking zone alongthe extended top corners of the baking basket when the baking basket hasbeen lowered into baking position. These small flanges 67 seal againststructural members 13 part of the toaster structure.

FIG. 10 shows the baking basket 7 partially inserted into thetoaster/baker and FIG. 9 shows the basket 7 fully inserted. The basketis lowered into place by the motor driven carriage 21. The base tray 8of the baking basket fits within and is held by the recess of thecarriage 21. The basket is positioned vertically by virtue of the closefit of basket end plates 64 with the walls of the toaster/baker topopening 16.

The motor driven carriage arm 21 extends through a slot in partition 59,FIG. 7, that encloses the toaster/baking zone and serves as a heatbarrier for the motor compartment. The far end of carriage arm 21extends into and is guided by enclosed slot 63. As the baking basket 7is lowered into the baking zone its end plate 64 slides in close contactwith partition 59 to seal off most of the air flow through the slot inpartition 59 through which the carriage arm extends.

The baking heater 44, FIGS. 7-10 is located below the carriage arm 21and under the food baskets. Heater 44 is also below horizontal shieldingplate 68 that prevents direct radiant energy emitted by the lamp heater44 from shining directly on the baking basket. It also shields theheater from any food particles that may fall from side of the foodbasket. On each side and slightly below that heater are crumb trays 46that can be constructed either as two separate units or joined by alower plate (not shown) so that they be removed together for cleaning.

In the baking mode the toasting heater cages remain in a retractedposition in order to allow the air from heater 44 to pass freely betweenthose heaters and the baking basket. The upper row of heater wires 40Aon the toasting boards and the lower row 40B are not permanentlyconnected together electrically and instead each row can be programmedto have full or partial line voltage across them or the rows can beconnected in series at full or partial line voltage. By this means theseelectrical toasting elements can be powered on full or partially toestablish the optimum amount of heat at their locations opposite thelarge vertical faces of the baking basket to compliment the air heatingmeans located below the horizontal partition plate 68. That plate 68 isjust large enough to shield direct radiation to the food and to protectthe lamp from falling debris or food particles, but not so wide as torestrict the flow of heated air passing up from the heater in the spacebetween the baking basket and the toaster heaters and passingconvectively through the food bed. Vertical walls 45 extend parallel toheater 44 on each side of the lower heater to confine and reinforce theair currents generated by the heater. These walls 45 extend from thebase of oven liner 12 to a height just short of the base of the movabletoasting cages 38.

The actuating arm 34, FIGS. 9 and 10, are actuated only by the toastingbasket. The baking basket does not contain the contact arms 32 needed tomove the actuating arms 34 which in turn tilts spring rod 35 to move thetoasting heater cages 38 in toward the toasting basket.

The typical baking cycle of this novel baking arrangement is shorterthan that in convectional home ovens for two reasons. Importantly ittakes much less time to heat up the baking zone. Further the improvednatural convection currents created by this combined heating arrangementinsures faster and more uniform heat transfer to the food surface.

Because of these advantages, with this new baking arrangement the totaltime required for oven heat-up plus baking is slightly less than thetime required just for baking in a conventional small toaster oven. Thefollowing example illustrates the advantage found in elapsed time whenbaking partially cooked but frozen foods in this new toaster/baker.

Frozen French Fries

Commercially available frozen french fries. These were precooked but notbrowned by manufacturer before freezing. These were removed frozen fromcommercial package and placed in oven promptly.

-   -   Conventional Toaster Oven—(Black & Decker TR0400, 1550 Watts)    -   Heat-up time—5 minutes to reach 450° F.    -   Baking time—30 minutes single layer—10 ounces French fries        (single layer on metal tray)    -   Total time—35 minutes to bake thoroughly    -   Toaster/Baker (described above—20 ounces French fries; twice the        quantity of french fries held by the Black & Decker toaster        oven) (1480 watts maximum) (basket size: 10.5 inches long, 5        inches high, 1.6 inch between vertical mesh faces)    -   Heat-up time—1½ minutes to reach 450° F.    -   Bake time—26 minutes    -   Total time—28 minutes to bake thoroughly    -   [It is evident that this new baking arrangement cooked in less        time twice as many french fries as the conventional        toaster/oven.]

The following baking sequence was used when baking with this new bakingapparatus:

-   -   Heat-up Period    -   Both upper and lower toaster elements 40A and 40B in both        toasting cages were energized on full voltage for 1½ minutes.        The bottom baking heater (680 watts) was also on at full voltage        for the heat-up period.    -   Baking Cycle    -   Following the heat-up cycle, the two lower toasting elements 40B        (800 watts) connected in series electrically and the bottom        baking heater 44 were each powered at 120 Volts by a solid state        relay, that adjusted the amount of power as necessary to        maintain temperatures at the set point.

The amount of power delivered during the baking cycle to these heaterssubsequent to the heat-up period was automatically controlled by thesolid state relay in accordance with the electrical signal received froma conventional thermocouple junction located on a post attached to onetoaster cage about ½″ in front of the toasting heater elements. Duringthe baking cycle the amount of required power was reduced to only afraction of the initial power as the oven and food surface reached thepreset control bake temperature. The control temperature for baking wasin each test selected and set manually at the temperature recommended bythe packager of the frozen food product.

A saving of about 20% in total time compared to conventional ovens andtoaster ovens was measured on a variety of frozen foods including: onionrings, french toast nuggets (450° F.), hot pockets (350° F.), cheesetoast (425° F.), croissant pockets (with sausage and cheese 350° F.) andhash brown potatoes (450°).

1. A baking basket for holding items of food to be cooked in a bakingoven, said baking basket comprising a pair of vertically disposed meshside walls each of which has a lower end and a pair of side edges, agenerally horizontal mesh bottom wall at said lower ends of and betweensaid mesh side walls, a solid tray mounted below and spaced from saidbottom wall to catch and contain any crumbs that will fall from foodplaced above, a respective solid closed end wall between each set ofadjacent side edges of said open framework formation side walls, atleast one mounting element for holding said side walls in an uprightvertical position generally parallel to each other, said side wallsbeing pivotally mounted at their lower ends to permit said side walls tobe disposed in a generally aligned flat condition, at least one of saidside walls having a cover lid at its upper end, said cover lid beingdisposed generally toward the other of said side walls to create a topfor said basket, and said cover lid of said at least one of said sidewalls being spaced from the other of said side walls to leave an air gapfor permitting hot air to escape out of said top of said basket.
 2. Thebasket of claim 1 wherein each of said end walls terminates at its topwith a handle to facilitate the holding of said basket.
 3. The basket ofclaim 1 wherein said mounting element comprises a retaining clip on eachof said end walls for engaging each of said side walls.
 4. The basket ofclaim 1 wherein said gap is about 1/4 inch wide.
 5. The basket of claim1 wherein said tray is connected to said bottom wall.
 6. The basket ofclaim 1 wherein said tray has a solid base, and said bottom wall beingat least 3/8 inches above said base.
 7. The basket of claim 1 whereinsaid bottom wall is formed by an inward projection at each of said lowerends of said side walls.
 8. The basket of claim 1 in combination with aheater member under said tray.
 9. The basket of claim 8 wherein saidheater member is elongated and has a longitudinal center line offsetfrom the longitudinal center line of said basket.
 10. The basket ofclaim 8 wherein said basket is shielded from direct radiation emittedfrom said heater member.
 11. The basket of claim 10 wherein said heatermember is located in a relatively open but roofed compartment below saidbasket.
 12. The basket of claim 8 wherein said heater member is anelongated heater member disposed longitudinally under the basket. 13.The basket of claim 12 including a vertically oriented heater elementjuxtaposed each of said side walls.
 14. The basket of claim 1 incombination with a vertically oriented heater element juxtaposed each ofsaid side walls.
 15. The basket of claim 1 wherein each of said sidewalls has a cover lid, and said cover lids being spaced from each otherto leave said air gap.
 16. The basket of claim 15 wherein said trayextends substantially the entire length of said bottom wall.
 17. Thebasket of claim 16 wherein each of said cover lids extends substantiallythe entire length of its side wall.
 18. The basket of claim 15 whereineach of said lids is hingedly mounted to its side wall.
 19. The basketof claim 18 including a closure latch on each of said cover lids mountedoutwardly away from its side wall.
 20. The basket of claim 15 includinga flange extending outwardly from each of said cover lids.